1. Technical Field
The present invention relates to an illumination device, which has a plurality of light emitting portions, and an electronic apparatus using the same.
2. Related Art
As illumination devices having a plurality of light emitting portions, there are known illumination devices which have a plurality of LED (Light Emitting Diode) elements and illumination devices that have a plurality of organic light emitting diode (Organic LED) elements, as described in JP-A-2007-87792 and JP-A-2007-171319. In such illumination devices, all the light emitting portions are arranged on a single substrate (a light emitting substrate), and thus the light emitted from the light emitting substrate passes through a light collection optical system, and reaches an illumination target surface.
In the technical fields thereof, in terms of effectively using illuminating light, there has been demand for an illumination device capable of illuminating a wider area. Accordingly, it is advantageous to illuminate a wider area by using the illumination device having a plurality of light emitting portions. However, in the illumination devices disclosed in JP-A-2007-87792 and JP-A-2007-171319, the irradiation area based on a single light emitting substrate is restricted so as to be narrow by the light collection optical system. That is, it is difficult to use the above-mentioned techniques in illuminating a wider area. Therefore, the first issue of the invention relates to a technique of widening the irradiation area based on a single light emitting substrate.
On the other hand, as a method of widening the irradiation area in the illumination device having the plurality of light emitting portions, there is a method of widening the area of the light emitting substrate. However, there is a limitation in widening the area of the light emitting substrate. As another method, there is a conceivable method of forming the illumination device by arranging a plurality of light emitting substrates. However, in this case, the illuminance of the area, which corresponds to the connection portion of the light emitting substrates, on the illumination target surface is drastically lower than the illuminance of the other area. Therefore, the second issue of the invention relates to a technique of illuminating the area corresponding to the connection portion of the light emitting substrates.